Inhibitory Effects and Mechanism of Tieguanyin Tea Extracts on LPS-induced Inflammatory Response in RAW264.7 Cells

The aim of this study was to investigate the inhibitory effects and the potential mechanism of Tieguanyin tea extracts on LPS-induced inflammatory response in RAW264.7 cells. Lipopolysaccharide was applied to RAW264.7 cells to establish an inflammatory model, and treated with indomethacin and different concentrations of Tieguanyin tea extract. Detected the secretion of NO and IL-6, qPCR was used to detected the gene expression of nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), tumor necrosis factor α (TNF-α), monocyte chemoattractant protein 1 (MCP-1) and interleukin-6 (IL-6). Western Blot was used to detect the relative expression of inflammation-associated protein kinase (IKKβ), nuclear factor κB inhibitor (IκB), nuclear factor κB p65 (NFκB p65) and its phosphorylated products. The results showed that Tieguanyin tea extracts could significantly decrease the secretions of NO and IL-6, the gene expressions of iNOS, COX-2, TNF-α, MCP-1 and IL-6, and the phosphorylations of IKKβ, IkB and p65. In summary, Tieguanyin tea extracts significantly inhibit the LPS-induced inflammatory response of RAW264.7 cells, which may be related with the inhibition of NF-κB signaling pathway.